Comparative LCA Scenarios for Urban Regeneration of Residential Building Stock. Application to an Existing High-density Urban Block in Bologna

The construction sector and the existing building stock are responsible for high environmental impacts. Effective measures for urban sustainable regeneration and reducing the impact of urban areas must address the use of circular solutions to increase the rate of materials reused and reusable and minimise raw materials usage and waste production. Also, nearly zero energy buildings (NZEBs) using only renewable energy sources (RES) without fossil fuels are essential to achieve the decarbonisation target proposed by the European Union by 2050. The comparison of three intervention scenarios, reconstruction (R), deep renovation (DR) and conservation (C), in three different periods (10, 30, and 60 years) using the Life Cycle Assessment method allows for the estimation of their environmental impact in terms of Global Warming Potential and Primary Energy. The experimental application to an existing urban block in the first urban periphery of Bologna (Italy) provides interesting results. In this case, DR is not the most cost-effective in the long term, but the R is the most successful. Further simulations on other existing urban blocks are necessary to extend the results and obtain valuable data to integrate into georeferenced maps used as decision-support tools by local actors to boost the climate neutrality transition.